District Heating Monitoring System Design

With the development of the industrialization and improvement of people’s living standard, energy consumption of the buildings is also expanding, so demand on heating system become higher and higher. Traditional distributed boiler room heating system has been difficult to meet the heating needs, so area central heating has become the trend of heating development.The paper’s issue came from a heating system of region in Mian Yang City and Sichuan Province. We combined the characteristics of the heating system, in order to meet the requirement of the heating system, designed this region central heating automatic control system. The design principle of system is to achieve local control and remote monitoring. According to the requirement of system, we determined to use SCADA system, and also we divided the system into two sub systems, the boiler control system and heat transform station control system, the both sub systems used SCADA system.First, the paper introduced the overall architecture of the system, then combined with the process flow of the boiler control system and heat transfer station control system to determine the equipment and meter, determined to use Siemens S7-300series PLC in low step, use configuration software iFIX of GE in high monitor step. The communication of boiler control system is selected by Ethernet, because of distribution of the heat transform stations, the communication of heat transform stations are selected by GPRS. Follow to design procedures of the system, selecting idea of structured programming, used PID regulator function block FB41in STEP7to achieve control of main system loops. At last, we realized the design of the PC monitoring system. We have designed main monitor screens, that could monitor the operating parameters, and these data parameters saved to history database in the form of reporter.After the debugging an operation, the system can real-time respond to the on-site conditions, and also can operate safely and reliable. The system realized automatic control of heating system, saved energy, reduced environmental pollution, and has achieved the intended purpose.